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kaplan qbank - strongman - Printable Version +- USMLE Forum - Largest USMLE Community (https://www.usmleforum.com) +-- Forum: USMLE Forum (https://www.usmleforum.com/forumdisplay.php?fid=1) +--- Forum: Step 2 CK (https://www.usmleforum.com/forumdisplay.php?fid=3) +--- Thread: kaplan qbank - strongman (/showthread.php?tid=245667) |
kaplan qbank - strongman - ArchivalUser - 11-23-2007 A 5-month-old male infant has a urine output of less than 0.1 mL/kg/hr shortly after undergoing major surgery. On examination, he has generalized edema. His blood pressure is 94/48 mm Hg, pulse is 140/min, and respirations are 20/min. His blood urea nitrogen is 38 mg/dL, and serum creatinine is 1.4 mg/dL. Initial urinalysis shows a specific gravity of 1.018 and 2+ protein. Microscopic examination of the urine sample reveals 1 WBC per high-power field (HPF), 18 RBCs per HPF, and 5 granular casts per HPF. His fractional excretion of sodium is 3.2 %. Which of the following is the most appropriate next step in diagnosis? A. CT of the abdomen and pelvis B. Cystourethrography C. Intravenous pyelography D. Renal biopsy E. Renal ultrasonography 0 - ArchivalUser - 11-23-2007 EEEEE BUN/Cr=38/1.4=27, he may have postrenal renal failure. So renal ultrasonic is indicated. 0 - ArchivalUser - 11-23-2007 this is atn ..as fc na is more than 2% and bun /cr is >10..granular cast too. 0 - ArchivalUser - 11-23-2007 ?? this is a pre-renal mechanism. 0 - ArchivalUser - 11-23-2007 this is renal problem...fr sodium is more than 1%.....initial investigation at this point is USG..E 0 - ArchivalUser - 11-23-2007 Answer is D This child has ATN secondary to hypotension after surgery as seen by tachycardia. ATN- granular casts and Fe Na-3.2%. So biopsy confirms the diagnosis. 0 - ArchivalUser - 11-23-2007 Sorry, I am confused. It is a typical ATN: proteinuria, granular casts and fractional excretion of sodium is3.2 %. So the acute renal failure results from ATN, which is caused by a ischemic or toxic injury to the kidney. U/S should be the initial step to evaluate the structural and anatomic changes of the kidney. E is the answer. 0 - ArchivalUser - 11-23-2007 Hi drdg, I am sorry. The diagnosis is ATN and the investigation of choice is ultrasound. If the cause of ATN is unnown , even after the ultrasound biopsy should be considered as a last resort here. |